YoSmart Fixes YoLink Smart Hub

In one issue, the YoSmart YoLink MQTT broker through 2025-10-02 does not enforce sufficient authorization controls to prevent cross-account attacks, allowing an attacker to remotely operate affected devices if the attacker obtains the associated device IDs. Because YoLink device IDs are predictable, an attacker can exploit this to gain full control over any other YoLink user’s devices.

CVE-2025-59449 is the case number for the issue, which has a CVSS V3 base score of 4.9.

Additionally, the YoSmart YoLink API through 2025-10-02 uses an endpoint URL derived from a device’s MAC address along with an MD5 hash of non-secret information, such as a key that begins with cf50.

CVE-2025-59452 is the case number for the vulnerability, which has a CVSS V3 base score of 5.8.

Another Vulnerability

Also, components of the YoSmart YoLink ecosystem through 2025-10-02 leverage unencrypted MQTT to communicate over the Internet. An attacker with the ability to monitor network traffic could therefore obtain sensitive information or tamper with the traffic to control affected devices. This affects YoLink Mobile Application 1.40.41 and YoLink MQTT Broker.

CVE-2025-59448 is the case number for the vulnerability, which has a CVSS V3 base score of 4.7.

Meanwhile, the YoSmart YoLink application through 2025-10-02 has session tokens with unexpectedly long lifetimes.

CVE-2025-59451 is the case number for the vulnerability, which has a CVSS V3 base score of 3.5.

The product sees use mainly in the communications sector, and on a global basis.

No exploit targets these vulnerabilities.

In terms of mitigations, for CVE-2025-59449 and CVE-2025-59451, YoSmart’s engineering team resolved these vulnerabilities on the server backend and the user does not need to take any action.

For CVE-2025-59448, YoSmart recommends users update to version 1.40.45 or later to mitigate this vulnerability.

For CVE-2025-59452, YoSmart released update 0383 to support a new, dynamic authentication algorithm. This will release as an automatic over-the-air update and no user action will end up required.

Click on the YoSmart security center for more information.